Objective: To evaluate the computed tomography (CT) findings compared with pathologic features and to determine whether CT findings are useful for diagnosis of appendiceal metastasis in patients with underlying malignancy.
Materials and Methods: Preoperative CT examinations of 59 patients who had underlying malignancy and underwent appendectomy were evaluated. Appendiceal metastasis (n = 21) and nonmetastasis (n = 38) were pathologically confirmed. Computed tomography features (appendiceal morphology and diameter, presence of ascites, rectal shelf, omental cake, lymphadenopathy or organ metastasis) were retrospectively reviewed, and compared with histopathological findings. Fisher exact test and Wilcoxon rank sum test were performed for statistical analysis.
Results: Mean diameter of appendiceal metastasis was significantly larger (9.1 mm) than that of nonmetastasis (5.2 mm), (P < 0.0001). The CT morphology of appendiceal metastasis showed broad spectrum, and 3 cases of nodular thickening was only detected in appendiceal metastasis. There was a significant difference between groups (P = 0.0102). Appendiceal metastasis was more frequently associated with peritoneal seeding (ascitis, rectal shelf, omental cake) than nonmetastasis (P < 0.0001). Histopathological invasion of appendiceal metastasis was more frequently seen in serosa-mesoappendix (n = 20, 100%) or muscularis propria (n = 17, 85%), than in submucosa (n = 10, 50%) or mucosa layer (n = 7, 35%). Acute appendicitis was more commonly detected in metastasis (n = 4) than in nonmetastasis (n = 1) (P = 0.0495).
Conclusions: Evaluation of CT features of appendix and peritoneum may be useful for prediction of appendiceal metastasis in patients with underlying malignancy.
From the *Department of Radiology, †Department of Pathology, ‡Department of Biomedical Sciences, Inha University School of Medicine, Inha University Hospital, Choong-gu Incheon, Republic of Korea; and §Department of Biology, New York University, New York, NY.
Received for publication November 23, 2015; accepted March 29, 2016.
Correspondence to: Mi Young Kim, MD, PhD, Department of Radiology, Inha University Hospital, 3-ga, Shinheung-dong, Choong-gu Incheon, 400–711, Republic of Korea (e-mail: firstname.lastname@example.org).
This study was supported from INHA University grant.
The authors declare no conflict of interest.